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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2011

Abstract

Mould growth on exterior coated cladding façades is an undesirable element and will often shorten the aesthetical service life. Mould growth on painted surfaces is influenced by type and concentration of film fungicides, the paint formulation and the wood substrate itself, and wooden cladding may experience exponential fungal deterioration caused by variation in the climatic factors, often within a small limited area. The objective of this study was to gain knowledge about which factors influence surface mould growth on coated and uncoated wooden cladding in an outdoor environment, with a special attention to modified wood substrates. The data are based on evaluation of mould growth coverage on outdoors exposed wood panels consisting of different combinations of wood substrates and surface finishes. Panels were exposed on three locations; Bogesund (Sweden), Birkenes and Sørkedalen (Norway). The panels were monitored up to 4.5 years. The analysis showed that coating typology and exposure time both had highly significant influences on mould growth. Furthermore, wood substrate, temperature and relative humidity had a significant influence on mould growth, but comparatively less than coating typology and exposure time. Siberian larch heartwood, copper-organic preserved Scots pine and Scots pine heartwood performed best among the wood substrates. Heartwood as wood type was less susceptible to mould growth than a mix of sapwood and heartwood wood and pure sapwood. Acetylated Scots pine as wood substrate and Aspen as wood species had lower resistance to mould growth than the other wood substrates and wood species, respectively. The physical surface structure of a paint film also influences the mould growth. A hard model paint was significantly more susceptible than the other model paints. A soft model paint performed best, with the least mould growth coverage. Aureobasidium pullulans (deBary) Arnaud was the dominating fungal species on all the wood substrates.

Abstract

A long-term increase in radial tree growth has been reported in tropical (Lloyd & Farquhar 2008), temperate (Spiecker 1996, Voelker et al. 2006), alpine (Rolland et al. 1998) and boreal forests (Hofgaard et al. 1999) over the last decades. Variations in forest growth patterns have been ascribed to different causes, such as longer growing seasons due to climate warming (Hu et al. 2010), changes in land management practices (Hunter & Shuck, 2002), nitrogen deposition (Magnani et al. 2007), and atmospheric CO2 enhancement (Voelker et al. 2006). Tree-ring analyses provide detailed information on the past growth of forests. In order to assess the effect of climate change on forest growth, non-climatic variation should be removed from treering series. The effect of endogenous (inter-tree competition) and exogenous (insects attacks, fires, storms, human influence, etc.) disturbances on tree-ring series can be detected and reduced by considering trees from different sites. Furthermore, as tree-ring width generally decreases as trees grow older and larger, age-related growth trend should be removed, to preserve climatic lowfrequency variability of chronologies. Different detrending methods used to remove non-climatic variations need to be adapted to the objectives of a particular study....

Abstract

A comparable series of specimens from spruce wood were pre-treated with sodium hydroxide, sodium hydroxide and hydrogen peroxide, or per-acetic acid sequences. The pre-treatments reduced the yield of pulps and their Kappa number noticeably, diminished the degree of polymerization moderately, and increased their brightness. One-step peroxide bleaching of pulps from the pre-treated spruce wood resulted in their higher brightness compared to bleached pulp from sound wood. From the viewpoint of improved properties of pulp, the most efficient were the sodium hydroxide/per-acetic acid and per-acetic acid/sodium hydroxide sequences. The pre-treatments did not influence mechanical strength of the obtained pulps significantly.